Since beginning operation in 2008 August, the telescope has performed all-sky surveys every 3 hours.
The recently improved sensitivity and spatial resolution of the instrument is enabled by the Pass 8 update [1]}.
The Pass 8 update, in its current version P8R3 [2]} offers a higher acceptance of detected photons and a narrower point spread function (PSF) at higher energies, allowing for better analysis of point sources at higher energies.
A main addition to the update was the inclusion of PSF quartiles.
The Fermi-LAT detected photons are divided into four quartiles,
categorized based on their reconstruction accuracy where PSF 0 has the lowest quality and PSF3 has the highest qualityhttps://fermi.gsfc.nasa.gov/ssc/data/analysis/documentation/Cicerone/Cicerone_LAT_IRFs/IRF_PSF.html.
This enables the observer to specify the PSF quality of the photons, to optimize between spatial resolution and sensitivity.
